Non-contact power supply technology represented by electromagnetic induction has been studied. The non-contact power supply technology is used in, for example, a shaver or an electric tooth brush. In recent years, with introduction of magnetic field resonance technology as a cue, non-contact power supply is actively developed again.
Further, there has been known a wireless power supply system transmitting power to a power reception antenna from a power transmission antenna by wireless method, the wireless power supply system having a detection unit detecting information related to a disposition state of the power reception antenna, plural driving units separately driving plural power transmission coils of the power reception antennas, and a control unit controlling current flowing through the power transmission coils via the driving units based on at least the information related to the disposition state of the power reception antenna (see, for example, Patent Literature 1).
Further, there has been known a non-contact power transmission device having N (N is an integer of 2 or larger) power transmission circuits and a control means controlling this N power transmission circuits, is which the power transmission circuits have a power transmission side LC tank circuit constituted of serially connected capacitors and a power transmission coil, and an oscillation circuit supplying power to this power transmission side LC tank circuit, the power transmission coils of the N-power transmission circuits are disposed in a matrix form, and the control means controls a phase of a signal generated by each oscillation circuit of the N power transmission circuits so that phases of changes of magnetic fields coming from at least two power transmission coils among the power transmission coils of the N power transmission circuits align in a power reception coil of a power reception circuit (see, for example, Patent Literature 2).    Patent Literature 1: Japanese Laid-open Patent Publication No. 2008-283789    Patent Literature 2: Japanese Laid-open Patent Publication No. 2011-199975